Dirty Old Woman
An old man and an old woman are sitting in a nursing home and the old man says "I bet you can't guess how old I am." The old woman says "okay, unzip your pants." The old man unzips his pants and the woman sticks here hand in and plays around for a minute, she pulls her hand out and says "you're 89." The old man looks at her increduously and asks "how did you know that?" The old woman says "you told me yesterday!"